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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 P2cycG3bssY+CyIUH8p9zGLzBRyLXGxeYUFNX0Hb0pY6qUHHSpjkwQGhEKYHewHi
 ZfL0JjzMJ3UX55zE8X1z5A==

<SEC-DOCUMENT>0001179110-04-000566.txt : 20040106
<SEC-HEADER>0001179110-04-000566.hdr.sgml : 20040106
<ACCEPTANCE-DATETIME>20040106174550
ACCESSION NUMBER:		0001179110-04-000566
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040102
FILED AS OF DATE:		20040106

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KESSLER ARMIN M
		CENTRAL INDEX KEY:			0001194185

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31279
		FILM NUMBER:		04511182

	BUSINESS ADDRESS:	
		STREET 1:		157 TECHNOLGY DRIVE
		CITY:			IRVINE
		STATE:			TX
		ZIP:			92618
		BUSINESS PHONE:		9497996700

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GEN PROBE INC
		CENTRAL INDEX KEY:			0000820237
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				330044608
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		10210 GENETIC CENTER DR.
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8584108000

	MAIL ADDRESS:	
		STREET 1:		10210 GENETIC CENTER DR
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2004-01-02</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000820237</issuerCik>
        <issuerName>GEN PROBE INC</issuerName>
        <issuerTradingSymbol>GPRO</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194185</rptOwnerCik>
            <rptOwnerName>KESSLER ARMIN M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>GEN-PROBE INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>10210 GENETIC CENTER DRIVE</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2004-01-02</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>164</value>
</transactionShares>
<transactionPricePerShare><value>36.47</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>676</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes></footnotes>
<ownerSignature><signatureName>/s/ R. William Bowen, Attorney-in-Fact</signatureName>
<signatureDate>2004-01-06</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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